This invention relates generally to enhanced television broadcasts including analog and digital broadcasts.
Enhanced television programming enables television programming, in analog or digital form, to be accompanied by additional content. In some embodiments, the additional content may be in the form of Internet-based content. With enhanced television technology, content creators (e.g., broadcasters) may transmit hypertext markup language (HTML) data along with the traditional television signals. Viewers may interact with the television broadcast via the Internet.
For example, enhanced features may be displayed on a television screen that enable the viewer to access the network's web site for related programming information. The related programming information may be additional advertising or additional details that are not readily incorporated into the television program itself, as examples. Thus, the user may selectively access additional information through an Internet connection.
A variety of standards exist for enhanced television broadcasts including the Advanced Television Enhancement Forum's (ATVEF) Enhanced Content Specification, Version 1.1, Revision 26, 1998-1999 (hereinafter referred to as the ATVEF specification). The ATVEF specification provides standards for the transmission and processing of triggers, resources and announcements together with television content to produce a digital or analog enhanced television transmission.
In order to announce the availability of interactive television resources, a trigger may be utilized. Announcements announce programming currently available to the receiver. A resource is a television enhancement or web content displayable in conjunction with a television broadcast as an enhanced or interactive program.
According to the ATVEF specification, there are two basic transport types, called transport type A and transport type B. In transport type A, the resource is accessed over the Internet and in transport type B, the resource is transmitted with the television content.
Triggers may include a Uniform Resource Locator and may optionally also include a human readable name, an expiration date and a script. Triggers that include a name attribute may be utilized to initiate enhancements either automatically or with user confirmation. The initial top-level page for an enhancement is indicated by a Uniform Resource Locator in the trigger. The script attribute provides a script fragment to execute within the context of the page containing a trigger receiver object.
The expires attribute provides a expiration time, after which the link is no longer valid. The expires attribute may be in the form [expires: 19971223] according to one example provided in the ATVEF specification.
In some cases, the link to the resource provided by the trigger may be caused to expire after a period of time. This may create problems. For example, in some situations, the enhanced television content may be retransmitted by a local affiliate or so-called franchise network operating center (FNOC). The FNOC may receive the broadcast and then retransmit it at an appropriate time, for example given the FNOC's local time zone. As a result, the expiration time may come and go before the broadcast is ever even transmitted. In such case, a user may be unable to activate the link to obtain the resource.
Similarly, digital recording technology may be available to enable the user to actually record an enhanced broadcast. The user may subsequently attempt to replay the recorded broadcast and may be unable to activate the links to the resource because the links have expired.
Thus, there is a need to enable time shifted enhanced television content to be used effectively in a variety of circumstances.